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User Manual: Contents | Guidelines | Blender Version 2.46

Particles are lots of items emitted from mesh objects, typically in the thousands. Each particle can be a point of light or a mesh, and be joined or dynamic. They may react to many different influences and forces, and have the notion of a lifespan. Dynamic particles can represent fire, smoke, mist, and other things such as dust or magic spells. Static particles form strands and can represent hair, grass and bristles.

Description

Image 1: Some neon-colored fur from particles

Particles generally flow out from their mesh into space. Their movement can be affected by many things, including:

• inital velocity out from the mesh
• movement of the emitter (vertex, face or object) itself
• movement according to "gravity" or "air resistance"
• influence of force fields like wind, vortexes or guided along a curve
• interaction with other objects like collisions
• partially intelligent members of a flock (herd, school, ...), that react to other members of their flock, while trying to reach a target or avoid predators.
• smooth motion with softbodyphysics (only Hair particlesystems).
• or even manual transformation with lattices Lattices.

Particles may be rendered as:

• Halos (for Flames, Smoke, Clouds)
• Meshes which in turn may be animated (e.g. fish, bees, ...). In these cases, each particle "carries" another object.
• Strands (for Hair, Fur, Grass); the complete way of a particle will be shown as a strand. These strands can be manipulated in the 3D window (combing, cutting, adding, cutting, moving, etc).

Every object may carry many particle systems. Each particle system may contain up to 100,000 particles. Certain particle types (Hair and Keyed) may have up to 10.000 children for each particle (children move and emit like their respective parents This is valid only for "children from particles". It's more complicated with children from faces.). The size of your memory and your patience are your practical boundaries.

You can have multiple sets of particle systems attached to an object, so, for example, you can have long fur as one system, and then very short fur mixed in. These particle systems can be mixed and matched and shared among many objects in your blend file.

There is one thing you can't do with the new system: you may no longer create branched static particle systems e.g. for very simple shrubbery. This functionality will probably be added in one of the following releases.

Workflow

The process for working with particle is:

1. Create the base mesh which will emit the particles. This mesh is not rendered by default, but the base material for the mesh is used to color the particles. Since a mesh can carry multiple materials, each particle system may have it's own material.
2. Create one or more Particle Systems to emit from the mesh. Many times, multiple particle systems interact or merge with each other to achieve the overall desired effect.
3. Tailor each Particle System's settings to achieve the desired effect
4. Animate the base mesh and other particle meshes involved in the scene
5. Define and shape the path and flow of the particles
6. (Only aplies to Hair particle systems): Sculpt the emitter's flow (cut the hair to length and comb it for example)
7. Make final render and do physics simulation(s), and tweak as needed

Creating a Particle System

Image 2: Adding a particlesystem

To add a new particle system to an object, go to the Particle sub-context of the Object [F7] context and click Add New in the Particle System tab. An object can have many Particle Systems. Therefore, when adding a Particle system, you may also:

• Select an existing particle system from the drop-down menu next to the Add New Button.
• Advance the active particle system (X Part Y) selector to an empty slot by clicking it near its right edge. As with material indices, the number to the left of Part indicates the active particle system, while the number on the right indicates the number of particle systems available for the object.
• Switch between already assigned Particle systems (X Part Y).
• Exchange one particle system for an other (for example PA:PSys.002 to PA:PSys.001)

Types of Particle systems

Image 3: Particlesystem types

After you have created a particle system, the button window fills with many panels and buttons. But don't panic! There are three different types of particle systems, and you can change between these three with the Type-Dropdown-Box:

Emitter

This parallels the old system to the greatest extent. In such a system, particles are emitted from the selected object from the Start frame to the End frame and have a certain lifespan. You may also render these kind of particles as strands (depending on the particle's physics).

Reactor

Reactor particles are born when other systems' particles do things. Usually, (not with emit from particles) the target particle's size determines it's area of influence. This is useful for most of the effects where you would have used children in the old particle system.

Hair

This system type is rendered as strands and has some very special properties: it may be edited in the 3D window in realtime and you can also animate the strands as Softbodies (similar to Softbody curves)

The settings in the Particle System panel are different for each system type. For example, in Image 3 they are shown for only system type Emitter.

Common Options

Each system has the same basic sets of controls, but options within those sets varies based on the system employed. These sets of controls are:

• Particle System - basic controls about quantity and quality
• Physics - how the particles behave
• Visualization - how to see the particles, in the 3D viewport and when rendered
• Extras - controlling emission, interaction and time
• Children - particles spawning more particles

Some individual settings are common for more than one particle system:

• Datablock selector (PA:): here you can select particle settings (browser button), name them (text field), or delete particle systems (X button)
• X Part Y: selector for the active particle system
• Enabled: toggle for enabling or disabling the active particle system
• Protect: the calculated movements of the particles are written to a subfolder (Blendcache_YourFileName) relative to the blendfile if you have saved the file. After saving you may play the particle animation back and forward in the 3D window and start it from any frame. Protect forces the actual particle simulation into the cache and locks it. Is Protect and caching still in the particle system?
• Clear: clears any previous particles simulation from the cache, but only from the current frame you're in. Change to frame 1 first if you want to clear the complete simulation. This may be a bug E.g. it may be necessary to clear the cache by hand if you change Ipo-Animations for the particles.
• Type: menu for selecting the type of particles.

Sections

Continue reading the appropriate section based on the type of particle system you have selected:

• Manual/Particles-Emitter
• Manual/Particles-Reactor
• Manual/Particles-Hair

Links

• Particle Rewrite Dokumentation
• Thoughts about the particle rewrite code

These links may be taken out later

• Static Particle Fur Library